Special Session organized by V. Ilić, J. Korbel and S. Gupta

Over the past decades, there has been an unprecedented interest in statistical physics of complex systems that are typically non-additive, nonextensive in Boltzmann-Gibbs framework and that exhibit long-lived non-Boltzmann stationary states accessible to observations. These systems are usually characterized by long-range interactions and/or correlations, path dependence and non-exponential phase-space growth, being studied by means of information theory, non-equilibrium thermodynamics and large deviation theory, as well as by means of generalized thermostatistics which is derived from additive and non-additive generalizations of Boltzmann-Gibbs entropy.
The goal of this section is to gather researchers from statistical physics and information theory communities in order to re-examine the role of generalized entropies and generalized thermostatistics in complex system modeling, with focus on mean-field spin systems, systems with emergent structures, nonequilibrium systems, multifractals, disordered systems, chaotic systems, and complex networks. Particularly, the section aims to explore the interplay between non-additivity, non-extensivity and generalized thermostatistics and to analyze their relationships to information theory and large deviations theory.

A non-exclusive list of topics of interest includes:

- Non-additivity and non-extensivity
- Heavy-tailed and thin-tailed distributions
- Generalized entropies and information measures
- Large deviation theory and central limit theorems

All the researchers from statistical physics and information theory who have an interest in the aforementioned fields are welcome to submit their contributions to this section.

Special Session organized by J. Zhang and H. Matsuzoe

Information geometry provides a suite of differential geometric tools for studying statistical inference, information theory, and machine learning models. Key notions such as statistical manifolds (with Fisher information as to its Riemannian metric), Hessian geometry, biorthogonal coordinates have links to statistical mechanics, thermodynamics, geometric mechanics, etc. As sequel to the special session (organized by Johnston, Matsuzoe, Ruppeiner, and Wada) at SigmaPhi2017, this Session at SigmaPhi2020 will explore differential geometric characterizations of probabilistic models arising from a variety of setting including stochastic thermodynamics, condensed matter physics, cosmology and high-energy physics, etc. Of particular interest are deformed statistical models, models which deviate from exponential family through parameterization (e.g., kappa-exponential model, q-exponential model, Renyi model) and their associated deformed entropy, cross-entropy, and divergences. The Session will also welcome contributions from related disciplines of statistical machine learning, dynamics and control, optimal transport and Wasserstein geometry, etc.  

Special Session organized by S. Ruffo and A. Trombettoni

The presence of non-local and long-range interactions in quantum systems induces several peculiar features in their equilibrium and out-of-equilibrium behavior. The interest in such systems grew in parallel with remarkable progress in current experimental platforms where control parameters such as interaction range, temperature and dimension can be changed. The Special Session will provide an occasion to present latest developments in the field and discuss open problems and perspectives.

Special Session organized by G. Parisi and E. Marinari

After more than forty years from the first, classical papers solving spin glass theory, the resulting paradigm allows us to describe a large number of complex systems and interactions. We will discuss many of them, trying to find common key issues and to improve our understanding of such a complex endeavor.